Apparatus for tensioning strip



1954 c. H. CAMPBELL 2,686,639

APPARATUS FOR TENSIONING STRIP Filed June 11. 1953 g ll/1111111454 URINE FURNACE HARDENING FURNACE DEGREASER INVENTOR. Char/es H. Gampbefl,

HIS ATTORNEY.

Patented Aug. 17, 1954 2,686,639 APPARATUS FOR TENSIONING STRIP Charles H. Campbell, Redford, Ohio, assignor to United States Steel Corporation, a corporation of New Jersey Application June 11, 1953, Serial No. 361,026

2 Claims. (01. 242-75) This invention relates to apparatus for tensioning strip and more particularly to apparatus for tensioning razor blade stock prior to its entry into a tempering line. Prior to my invention, various means were used for tensioning the strip prior to its entry into the hardening furnace. The use of felt wearing pads bearing against each side of the strip was common, but they were unsatisfactory in many respects, including non-uniform tensioning of the strip. Other tensioning means were also used without success since they too resulted in non-uniform tensioning of the strip. One result of non-uniform tensioning is the formation of short crooks or camber in the tempered strip.

It is an object of my invention to provide a tensioning device for strip tempering in which the tension applied will be uniform irrespective of variations in the thickness of the strip.

This and other objects will be more apparent after referring to the following specification and attached drawings, in which:

Figure 1 is a schematic view of a strip hardening furnace incorporating my invention;

Figure 2 is an enlarged side elevation of the tensioning device of my invention;

Figure 3 is a sectional view taken on the line III-III of Figure 2;

Figure 4 is an enlarged side elevation of a quench block used in the line of Figure 1; and

Figure 5 is an end elevation of Figure 4.

Referring more particularly to the drawings, the reference numeral 2 indicates a reel for supporting the coil of strip S to be hardened. From the reel 2 the strip passes through a degreaser 4 and under idler roll 6 to a hardening furnace 8. The tensioning device I of my invention is located between the roll 6 and the furnace 8. From the hardening furnace the strip passes through the cooling block l2, draw furnace l4, cooling block l and draw-out mechanism IE to the takeup block l8.

As shown in Figures 2 and 3, the tensioning device includes a supporting block which loosely carries a tungsten carbide wear plate 22. A similar tungsten carbide wear plate 24 is mounted above the plate 22 and a removable weight is mounted on top of the tungsten carbide block 24. A retainer plate 21, having an opening therethrough for the strip S, is fastened to the exit end of block 20 to prevent longitudinal movement of the wear plates. When threading the strip S through the processing line the block 24 and weight 26 are removed and a shim 28 of approximately the same thickness as the strip S is mounted on top of the tungsten carbide plate 22 adjacent the longitudinal edge of the wear plate. The strip S is passed over the wear plate 22 along the opposite longitudinal edge. The Wear plate 24 and weight 26 are then placed on top of the shim 28 and strip S. By use of this arrangement the back tension applied to the strip S will be relatively uniform regardless of variations in the thickness of the strip which often occurs. The amount of tension can be varied by changing the size of weight 26. As the strip S passes between the wear plates 22 and 24 any burrs that might be on the strip will be at least partially removed.

The cooling block I 2 may be of the type shown in the patent to Harasty No. 2,638,337, dated May 12, 1953. In some instances, especially when treating relatively wide strips, that is, strips of several inches in width, a somewhat modified quench block is used as shown in Figures 4 and 5. The lower quench block 30 will be the same as that in the Harasty patent but the top quench block 32 Will be made in sections 32a, 32b, 32c, 32d and 32e. Each quench block is provided with a water inlet 35 and outlet 36 and the construction of each block is similar to that of the single quench block of the Harasty patent. This quench block also differs from that of the Harasty patent in that a single shim 38 of approximately the same thickness as the strip S is mounted on the lower tungsten carbide plate 40 with the strip and shim supporting the upper tungsten carbide plates 42. A plate 42 is provided under each section of the top quench block 32. The arrangement of this shim and strip is substantially the same as that in the tensioning device H). An exit guide 44 holds the tungsten carbide plates, shim 38 and upper quench block 32 in place. This multiple section top block enables each zone of quenching to be controlled, maintains a more uniform area of contact with the strip and eliminates scratching.

While one embodiment of my invention has been shown and described it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

1. In a continuous strip processing line, apparatus for applying back tension to the strip prior to its entry into the processing equipment comprising an elongated bottom wear plate of hard smooth material mounted below the path of travel of said strip, an elongated top wear plate of similar material mounted above said bottom wear plate, each of said wear plates being substantially wider than said strip, a shim of substantially the same thickness as said strip mounted between said wear plates adjacent one longitublock, a top tungsten carbide wear plate mounted above said bottom tungstencarbide, 1 wear. plate, each of said wear plates being substantially wider than said strip, a shim of substantially thejsa-me thickness as said strip mounted between said wear plates adjacent one longitudinal edge thereof, said strip passing between said wear plates adjacent the other longitudinal edge thereof, and a weight restingon top of said top wear plate.

References Cited in the file of this patent UNITED STA 'I ES- PATENTS Number Name Date 1,386,813 Townsend Aug. 9, 1921 1,862,727 Thordarson June 14, 1932 -2;1,44-,264 W.McRae et a1. Jan. 17, 1939 2,285,733 Martel June 9, 1942 --"-2,451;889 'Toone Oct. 19, 1948 

